{"affected":[{"defaultStatus":"unaffected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"lessThan":"14f5549ad163be2c018abc1bb38370fff617a243","status":"affected","version":"000dbe0bec058cbf2ca9e156e4a5584f5158b0f9","versionType":"git"},{"lessThan":"5bf0b9eeb0174686f22c2e5b8fb9f47ad25da6f5","status":"affected","version":"000dbe0bec058cbf2ca9e156e4a5584f5158b0f9","versionType":"git"},{"lessThan":"1e93b61d3eaa14bfebcc2716ac09d43f3845d420","status":"affected","version":"000dbe0bec058cbf2ca9e156e4a5584f5158b0f9","versionType":"git"},{"lessThan":"4c10fa44bc5f700e2ea21de2fbae520ba21f19d9","status":"affected","version":"000dbe0bec058cbf2ca9e156e4a5584f5158b0f9","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"status":"affected","version":"6.4"},{"lessThan":"6.4","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.95","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.35","versionType":"semver"},{"lessThanOrEqual":"6.15.*","status":"unaffected","version":"6.15.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.16","versionType":"original_commit_for_fix"}]}],"cveId":"CVE-2025-38338","cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/nfs/read: fix double-unlock bug in nfs_return_empty_folio()\n\nSometimes, when a file was read while it was being truncated by\nanother NFS client, the kernel could deadlock because folio_unlock()\nwas called twice, and the second call would XOR back the `PG_locked`\nflag.\n\nMost of the time (depending on the timing of the truncation), nobody\nnotices the problem because folio_unlock() gets called three times,\nwhich flips `PG_locked` back off:\n\n 1. vfs_read, nfs_read_folio, ... nfs_read_add_folio,\n    nfs_return_empty_folio\n 2. vfs_read, nfs_read_folio, ... netfs_read_collection,\n    netfs_unlock_abandoned_read_pages\n 3. vfs_read, ... nfs_do_read_folio, nfs_read_add_folio,\n    nfs_return_empty_folio\n\nThe problem is that nfs_read_add_folio() is not supposed to unlock the\nfolio if fscache is enabled, and a nfs_netfs_folio_unlock() check is\nmissing in nfs_return_empty_folio().\n\nRarely this leads to a warning in netfs_read_collection():\n\n ------------[ cut here ]------------\n R=0000031c: folio 10 is not locked\n WARNING: CPU: 0 PID: 29 at fs/netfs/read_collect.c:133 netfs_read_collection+0x7c0/0xf00\n [...]\n Workqueue: events_unbound netfs_read_collection_worker\n RIP: 0010:netfs_read_collection+0x7c0/0xf00\n [...]\n Call Trace:\n  <TASK>\n  netfs_read_collection_worker+0x67/0x80\n  process_one_work+0x12e/0x2c0\n  worker_thread+0x295/0x3a0\n\nMost of the time, however, processes just get stuck forever in\nfolio_wait_bit_common(), waiting for `PG_locked` to disappear, which\nnever happens because nobody is really holding the folio lock.","epss":{"date":"2026-11-05","percentile":0.08201,"score":0.00185},"exploits":[],"kev":null,"metrics":[],"modifiedAt":1793912554128,"publishedAt":1752135309022,"references":[{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/14f5549ad163be2c018abc1bb38370fff617a243"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/5bf0b9eeb0174686f22c2e5b8fb9f47ad25da6f5"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/1e93b61d3eaa14bfebcc2716ac09d43f3845d420"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/4c10fa44bc5f700e2ea21de2fbae520ba21f19d9"}],"remediation":[],"revision":"11bd3541143562fff13c96deefd9186ef29106d19db4de30b2bb6a8bae108013","sources":[{"modifiedAt":1793912554128,"name":"CNA: Linux","retrievedAt":1793913667813,"url":"https://www.cve.org/CVERecord?id=CVE-2025-38338"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793913669924,"url":"https://api.first.org/data/v1/epss?cve=CVE-2025-38338"}],"ssvc":{"assessedAt":1793912100358,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"fs/nfs/read: fix double-unlock bug in nfs_return_empty_folio()","updatedAt":1793913669924}